Amino benzaldehyde compounds are useful as agrochemical/pharmaceutical intermediates as disclosed in Patent Document 3 or Patent Document 4. Various methods for producing amino benzaldehyde compounds have been proposed.
For example, Patent Document 1 discloses a method for producing a 2-amino benzaldehyde compound by reacting triazanonane with an acid (see formulae (1)).

Patent Document 2 discloses a 3-fluoro-4-chloro-6-aminobenzaldehyde. The compound is obtained by conducting contact hydrogen reduction of 3-fluoro-4-chloro-6-nitrobenzaldehyde using a platinum-containing catalyst or a ruthenium-containing catalyst in an organic solvent under increased pressure. Patent Document 3 discloses 2-amino-3-methoxybenzaldehyde derivatives.